RE: Multi-precision (was...Please give me advice)
I think what Michel was referring to was that one of the main origins of intervals in inputs is measurements, if we have a measurement result X and the only info info that we know about the measurement error X-x is the upper bound D, this means that the actual (unknown) value of the measured quantity is somewhere within the interval [X-D,X+D]. This is mid-rad. In measurement data processing practice, this is the usual input, so naturally, when an interval is represented in a different way, it makes sense to transform it to mid-rad form to be able to use known algorithms for processing data with uncertainty.
-----Original Message-----
From: stds-1788@xxxxxxxx [mailto:stds-1788@xxxxxxxx] On Behalf Of Vincent Lefevre
Sent: Friday, October 15, 2010 8:12 AM
To: stds-1788
Subject: Re: Multi-precision (was...Please give me advice)
On 2010-10-15 06:42:58 -0400, Michel Hack wrote:
> This discussion again suffers from the one-sided view that intervals
> represent uncertain numbers.
>
> When intervals are used to express ranges of values, the concept of a
> midpoint frequently doesn't even make sense.
But one wouldn't normally use mid-rad to express ranges of values;
inf-sup is more suited for that.
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon)